/*************************************************************************
	> File Name: oj-393_cut_rope.cpp
	> Author: Wang Bo
	> Mail: 1276106221@qq.com
	> Created Time: 2020年11月01日 星期日 18时20分52秒
 ************************************************************************/

#include <iostream>
#include <cstdio>
using namespace std;

int n, m;
double num[100005], tr;
const double epsl = 0.00001;

int func(double len) {
    int s = 0;
    for (int i = 0; i < n; ++i) {
        s += num[i] / len;
    }
    return s;
}

int main() {
    cin >> n >> m;
    for (int i = 0; i < n; ++i) {
        cin >> num[i];
        tr = max(tr, num[i]);
    }
    double l = 0, r = tr;
    while (r - l > epsl) {
        double mid = (l + r) / 2;
        int s = func(mid);
        if (s >= m) l = mid;
        else r = mid;
    }
    printf("%.2f\n", (int)(l * 100) / 100.0);
    return 0;
}
